shaba/systemd-stable
1
1
Fork 0
mirror of https://github.com/systemd/systemd-stable.git synced 2024-10-27 10:25:06 +03:00
Code

Merge pull request #11212 from keszybz/mount-storm-revert

Browse Source 
Revert the patches for mount-storm prevention for now
This commit is contained in:
Chris Down 2018-12-19 12:11:15 +00:00 committed by GitHub
commit 2141bedb39
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 7 additions and 100 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
src/core/manager.h
View File

@ -227,10 +227,6 @@ struct Manager {
/* Data specific to the mount subsystem */
struct libmnt_monitor *mount_monitor;
sd_event_source *mount_event_source;
sd_event_source *mount_timeout_source;
usec_t mount_last_read_usec;
usec_t mount_last_duration_usec;
unsigned mount_pending_count;
/* Data specific to the swap filesystem */
FILE *proc_swaps;

103
src/core/mount.c
View File

@ -55,7 +55,6 @@ static const UnitActiveState state_translation_table[_MOUNT_STATE_MAX] = {
static int mount_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata);
static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata);
static int mount_dispatch_proc_self_mountinfo_timer(sd_event_source *source, usec_t usec, void *userdata);
static bool MOUNT_STATE_WITH_PROCESS(MountState state) {
return IN_SET(state,
@ -218,12 +217,6 @@ static void mount_done(Unit *u) {
assert(m);
if (!IN_SET(m->state, MOUNT_DEAD, MOUNT_MOUNTED, MOUNT_FAILED)) {
/* This was pending, so need to udpate the count */
assert(u->manager->mount_pending_count > 0);
u->manager->mount_pending_count--;
}
m->where = mfree(m->where);
mount_parameters_done(&m->parameters_proc_self_mountinfo);
@ -656,7 +649,6 @@ static int mount_load(Unit *u) {
static void mount_set_state(Mount *m, MountState state) {
MountState old_state;
int was_pending, is_pending;
assert(m);
if (m->state != state)
@ -665,17 +657,6 @@ static void mount_set_state(Mount *m, MountState state) {
old_state = m->state;
m->state = state;
was_pending = !IN_SET(old_state, MOUNT_DEAD, MOUNT_MOUNTED, MOUNT_FAILED);
is_pending = !IN_SET(state, MOUNT_DEAD, MOUNT_MOUNTED, MOUNT_FAILED);
if (was_pending && !is_pending) {
assert(UNIT(m)->manager->mount_pending_count > 0);
UNIT(m)->manager->mount_pending_count--;
}
if (is_pending && !was_pending)
UNIT(m)->manager->mount_pending_count++;
if (!MOUNT_STATE_WITH_PROCESS(state)) {
m->timer_event_source = sd_event_source_unref(m->timer_event_source);
mount_unwatch_control_pid(m);
@ -1684,7 +1665,6 @@ static int mount_load_proc_self_mountinfo(Manager *m, bool set_flags) {
static void mount_shutdown(Manager *m) {
assert(m);
m->mount_timeout_source = sd_event_source_unref(m->mount_timeout_source);
m->mount_event_source = sd_event_source_unref(m->mount_event_source);
mnt_unref_monitor(m->mount_monitor);
@ -1800,55 +1780,13 @@ fail:
mount_shutdown(m);
}
static void mount_process_proc_self_mountinfo(Manager *m);
static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
_cleanup_set_free_free_ Set *around = NULL, *gone = NULL;
Manager *m = userdata;
const char *what;
Iterator i;
Unit *u;
int r;
usec_t next_read = usec_add(m->mount_last_read_usec,
m->mount_last_duration_usec * 10);
/* If there are pending mounts initiated by systemd, then
* we need to process changes promptly, otherwise we
* rate limit re-reading the file.
*/
if (m->mount_pending_count == 0 &&
now(CLOCK_MONOTONIC) < next_read) {
/* The (current) API for getting mount events from the Linux kernel
* involves getting a "something changed" notification, and then having
* to re-read the entire /proc/self/mountinfo file. When there are lots
* of mountpoints, this file is large and parsing it can take noticeable
* time. As most of the file won't have changed, this can be seen as wasted time.
* If there is a "mount storm" such as 1000 mount points being created
* in quick succession, this will result in 1000 successive notification.
* If we respond to every notification, we will do quadratically more work
* than if we respond just once after all the notifications have arrived.
* In this (pathological) case, a delay in scheduling would actually
* improve throughput as we would combine notifications and parse
* the file less often. We cannot expect the scheduler to notice
* this pathology without help.
* So when the rate of notifications means we are spending more than
* 10% of real time handling them, we set a timer and stop listening
* to notifications for a while.
* If/when Linux provides an API which provides only details of what
* has changed, this rate-limiting can be removed.
*/
r = sd_event_source_set_enabled(source, SD_EVENT_OFF);
if (r < 0)
log_warning_errno(r, "Failed to disable monitoring of /proc/self/mounting, ignoring: %m");
if (!m->mount_timeout_source) {
r = sd_event_add_time(m->event, &m->mount_timeout_source,
CLOCK_MONOTONIC,
next_read,
0,
mount_dispatch_proc_self_mountinfo_timer,
m);
if (r < 0)
log_warning_errno(r, "Failed to set timeout to reread /proc/self/mounting, ignoring: %m");
}
return 0;
}
assert(m);
assert(revents & EPOLLIN);
@ -1876,40 +1814,13 @@ static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents,
return 0;
}
mount_process_proc_self_mountinfo(m);
return 0;
}
static int mount_dispatch_proc_self_mountinfo_timer(sd_event_source *source, usec_t usec, void *userdata) {
Manager *m = userdata;
int r;
r = sd_event_source_set_enabled(m->mount_event_source, SD_EVENT_ON);
if (r < 0)
log_warning_errno(r, "Failed to reenable /proc/self/mountinfo monitor, ignoring: %m");
m->mount_timeout_source = sd_event_source_unref(source);
mount_process_proc_self_mountinfo(m);
return 0;
}
static void mount_process_proc_self_mountinfo(Manager *m) {
_cleanup_set_free_free_ Set *around = NULL, *gone = NULL;
const char *what;
Iterator i;
Unit *u;
int r;
m->mount_last_read_usec = now(CLOCK_MONOTONIC);
/* If an error occurs, assume 10ms */
m->mount_last_duration_usec = 10 * USEC_PER_MSEC;
r = mount_load_proc_self_mountinfo(m, true);
if (r < 0) {
/* Reset flags, just in case, for later calls */
LIST_FOREACH(units_by_type, u, m->units_by_type[UNIT_MOUNT])
MOUNT(u)->proc_flags = 0;
return;
return 0;
}
manager_dispatch_load_queue(m);
@ -1997,8 +1908,8 @@ static void mount_process_proc_self_mountinfo(Manager *m) {
/* Let the device units know that the device is no longer mounted */
device_found_node(m, what, 0, DEVICE_FOUND_MOUNT);
}
m->mount_last_duration_usec = usec_sub_unsigned(now(CLOCK_MONOTONIC),
m->mount_last_read_usec);
return 0;
}
static void mount_reset_failed(Unit *u) {